Algorithms For Dummies

Considering the essence of a graph

Graphs appear as ordered pairs in the form G = (V,E), where G is the graph, V is a 

list of vertexes, and E is a list of edges that connect the vertexes. An edge is actu-

ally a numeric pair that expresses the two vertexes that it connects. Consequently, 

if you have two vertexes that represent cities, Houston (which equals 1) and Dallas 

(which equals 2), and you want to connect them with a road, then you create an 

edge, 

Highway

, that contains a pair of vertex references, 

Highway = [Houston, 

Dallas]

. The graph would appear as 

G = [(Houston, Dallas)]

, which simply 

says that there is a first vertex, Houston, with a connection to Dallas, the second 

vertex. Using the order of presentation of the vertexes, Houston is adjacent to 

Dallas; in other words, a car would leave Houston and enter Dallas.

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CHAPTER 8